Cytokines are soluble glycoproteins or small peptides released by living cells such as parenchyma, endothelium and leucocytes. Cytokines having an effect on inflammation may be conveniently subdivided into pro and anti inflammatory. A chemokine is a cytokine that acts as an attractant to other cells.
These soluble glycoproteins and peptides are released from living cells such as macrophages and lymphocytes in response to noxious stimuli such as ischemia, endotoxin, physical and chemical injury. They may be conviently subdivided into pro and anti-inflammatory cytokines.
Pro-inflammatory cytokines are predominantly released by macrophages and up
regulate inflammatory reactions. Anti-inflammatory cytokines are predominantly
released by T lymphocytes and are involved with down regulating the
inflammatory response. Transforming growth factor 
(TGF-
) has both pro
and anti inflammatory effects.